"A replacement for the South Korean K200-series infantry fighting vehicles, formerly designated as K300 or XK21 KNIFV (Korea Next-generation Infantry Fighting Vehicle), is currently called the K21. The initial production was set for 2008, with the Republic of Korea Army planning to field approximately 466 units. It is designed to effectively defeat other IFVs as heavily armed and armored as the BMP-3…

The two-man turret on the K21 is armed with an S&T Dynamics K40 40 mm cannon[1] capable of firing APFSDS, high-explosive, smoke and multipurpose munitions, and a 7.62 mm machine gun. This is combined with an advanced fire-control system and gun stabilizer usually found on third-generation main battle tanks that makes the K21, together with the German Puma, able to move and engage the targets with high degree of accuracy at the same time. The ammunition for the autocannon is stored under the turret. The 40 mm cannon can fire up to 300 rounds per minute, with a projectile velocity of up to 1,005 m/s (3,300 ft/s). The improved APFSDS rounds fired from it is able to penetrate up to 160–220 mm (6.3–8.7 in) of armor, slightly higher than other APFSDS rounds, due to the self-sharpening process as the round penetrates the armour…"From Wiki